The present invention generally relates to medical devices and tissue engineering compositions, and more particularly, to devices, methods and compositions for sealing tissue puncture openings of patients after surgical operations.
Certain medical procedures require the invasion of a patient""s artery by creating a puncture opening in a patient""s skin and subcutaneous tissue. For example, in a percutaneous transluminal coronary angioplasty (PTCA), it is common practice to insert an introducer catheter into the patient""s artery through the surface of the skin and the underlying tissue. Thereafter, a balloon catheter or other type of catheter is inserted into the artery to perform various medical tasks. After the procedure, bleeding through the puncture opening is unavoidable and must be stopped. Very often, continuous bleeding is prevented by applying digital pressure on the puncture site for a prolong duration until hemostasis occurs. This practice is riddled with various problems. To begin with, the pressure normally has to be applied in excess of 30 minutes under the intense care of a medical practitioner. Furthermore, the hemostasis closure thus formed is quite often unreliable and susceptible to rupture causing undesirable consequences. In addition, pressuring the artery yields the effect of thrombosis, which restricts the blood flow to a patient during the post surgical period and consequently may cause unwanted complications.
Devices that are useful for replacing the manual pressuring method described above have previously been described. For example, U.S. Pat. No. 4,744,364 to Kensey, entitled xe2x80x9cDevice for Sealing Percutaneous Puncture in a Vessel,xe2x80x9d which issued on May 17, 1988, describes a protocol that includes first deploying a flat and flexible sealing member into the patient""s blood vessel. The sealing member is attached to a drawstring. At the end of the sealing procedure, the drawstring is tightened resulting in the flexible sealing member collapsing on the inner wall of the blood vessel at the puncture site. The sealing member and the drawstring are secured in place on the patient""s skin surface with an adhesive tape.
There are several drawbacks associated with Kensey""s approach. First, since the device is deployed inside the blood vessel, fragmentation or disintegration of the sealing member may result in foreign objects introduced into the patient""s blood stream. As a consequence, embolism may develop in the patient""s blood system. Furthermore, the sealing member and the puncture opening have to be in good alignment to be effective. Misalignment can leak blood into the patient""s subcutaneous tissue leading to hematoma as a repercussion.
To avoid the aforementioned shortfalls, there have been suggestions to deploy swellable, resorbable materials in the subcutaneous tissue at the puncture sites outside the vessels for sealing the puncture wounds. For example, U.S. Pat. No. 5,437,631, to Jenzen, entitled xe2x80x9cPercutaneous Introducer Set and Method for Sealing Puncture Wounds,xe2x80x9d which issued on Aug. 1, 1995, describes a device that is used to deliver a swellable, resorbable material to the puncture site atop the blood vessel to seal the puncture wound. To practice this method, a secondary dilator first has to be inserted into the original puncture wound for additional puncture opening enlargement. Second, the secondary dilator has to be attached with a blunt nose coated with a contrast medium. In addition, the contrast medium must be administered to the blood stream, so that during operation, the position of the blunt nose in respect to the blood vessel is visible under fluoroscopy. The reason for the elaborated steps involved as taught by Jenzen is because the implant material has to be delivered to the puncture site precisely atop the vessel puncture opening. Delivery of the implant material other than the intended location can result in any of the complications mentioned above in association with Kensey""s device.
U.S. Pat. No. 5,571,181 to Li, entitled xe2x80x9cSoft Tissue Closure Systems,xe2x80x9d which issued Nov. 5, 1996, discloses a device that needs no additional enlargement of the original puncture opening. The use of Li""s device also does not require the introduction of a contrast medium in conjunction with the various fluoroscopy steps. However, the teaching of Li still does not provide a good way of ensuring that the implant material is delivered precisely to the desired targeted location. That is, to avoid the various consequential effects such as hematoma and embolism, the implant material has to be precisely seated atop the puncture opening of the blood vessel at the puncture site. Instead, Li teaches the delivery of the implant material midway in the tissue at a distance above the blood vessel puncture opening. The remainder of the void is sealed by the patient""s own blood clot. Thus, the practice of Li""s method may result in hematoma. This is especially true when the blood in the remainder of the void does not clot fast enough, because it is blocked off from any external exposure by the swollen implant material and further by the subsequent application of the sealing tape.
U.S. Pat. No. 5,868,778 to Gershony et al., entitled xe2x80x9cVascular Sealing Apparatus and Method,xe2x80x9d which issued on Feb. 9, 1999, is a method in which an attempt is made to seal the puncture site precisely above the blood vessel. The method of Gershony et al. involves the deployment of a deflated balloon housed in a reaccess sheath into the blood vessel through an introducer sheath. After deployment, the balloon is inflated and pulled proximally. The inflated balloon acts as a temporary hemostatic seal blocking the puncture opening of the blood vessel during normal operation. Then, liquid procoagulant is injected into the introducer sheath. While the procoagulant is in the process of coagulating, the balloon is deflated and then pulled out along with the reaccess sheath. The timing of pulling out the balloon in practicing Gershony et al.""s method is critical and is difficult to control. Pulling out the balloon and the reaccess sheath too soon may end up with the liquid procoagulant dripping into the patient""s blood stream and consequently increasing the possibility of embolism. Pulling out the balloon and the reaccess sheath too late after the procoagulant substantially coagulates may leave a trail of void after withdrawal, which directly leads to the patient""s blood stream and renders the sealing method ineffective.
The success of the aforementioned procedures also depends on the hemostatic efficiency of the biomaterials used to seal the puncture site. Various biomaterials such as collagen and synthetic polymers with hemostatic properties have previously been described and can be adapted for use in the present application. See, e.g., U.S. Pat. Nos. 3,742,955; 4,066,083; 4,891,359; 4,412,947; 4,578,067; 4,515,637; 4,271,070; 4,891,359; 4,016,877; 5,162,430; 5,324,775; and 5,874,500. Expandable implant materials have also been described that are capable of rehydration after insertion, which causes the implant to swell and become affixed in place. See, e.g., U.S. Pat. Nos. 5,326,350; 5,571,181; and PCT WO 98/30141.
In the practice of sealing puncture openings after surgical operations, complications associated with hematoma and embolism are real concerns. In a survey review publication edited by Lansky, et al., entitled xe2x80x9cTCT X Factoids: A Comprehensive Review of the Interventional Cardiovascular Literature,xe2x80x9d page 344 (1997-1998), it is stated that the proportion of operations using existing puncture wound closure devices resulting in any complications is 16.8%, in comparison with relying on the conventional method of digital pressure as mentioned above with a corresponding number of only 10.9%. The proportions are even more skewed with respect to major complications, which is 4.0% when devices are relied on as compared to 2.5% when manual compression is used. Phrased differently, the use of existent closure devices in performing puncture wound closure may shorten the healing time but increase the danger of inflicting various serious complications on the patient. Accordingly, there has been a long felt need to provide puncture opening closure devices that shorten recovery time, minimize unwanted complications after operations, and are easy to use.
It is accordingly an object of the invention to provide a tissue puncture opening closure device and method that minimize post-surgical complications.
It is another object of the invention to provide a tissue puncture opening closure device and method that are simple to use and easy to operate without unnecessary intermediate steps.
It is yet another object of the invention to provide a tissue puncture opening closure device and method that are inexpensive to manufacture and operate.
It is still another object of the invention to provide compositions for use in sealing tissues puncture openings and methods for using such compositions.
The present invention accomplishes the foregoing objectives by providing the puncture wound sealing apparatus that includes a positioning device having a depth sensing mechanism capable of providing feedback to an operator for the precise placement of an implant. After a percutaneous transluminal coronary angioplasty (PTCA), for example, the introducer sheath remains inserted in the patient""s artery. The operator retains the introducer sheath at the puncture wound site and accurately positions the sheath relative to the artery based on the feedback provided by the depth sensing mechanism as a prelude for precise implant placement. Via a novel approach relying on the natural elasticity of the patient""s blood vessel, the feedback can be in the form of fluid monitoring between the gap space formed between the positioning device and the bore of the introducer sheath. Alternatively, the distal end of the positioning device can be made extendable and the feedback can be in the form of resistance force experienced by the operator when the extended distal end encounters obstacles. Once the introducer sheath is accurately positioned, an implant made of swellable, resorbable material is precisely delivered to the patient via the sheath sealing the puncture wound, thereby substantially minimizing occurrences of consequential complications such as embolism and hematoma.
The present invention also concerns an implant adapted for sealing a tissue puncture opening outside a blood vessel of a living being, wherein the implant is made from a dried, swellable, resorbable matrix of, e.g., polyethylene glycol and gelatin in a weight ratio of between 1:3 and 3:1. Such implants provide for enhanced expansion properties and are well adapted for the procedures described herein.
In addition, the present invention concerns methods for sealing puncture openings outside a blood vessel using biomaterials that are adapted for formation of an implant capable of sealing such a tissue puncture opening. These materials need not be predried before implantation, but can be applied in liquid or gel form (or a combination of a liquid/gel and dry material(s)) at the tissue puncture opening and thereafter form a matrix that is strong enough to seal the opening.
In yet another embodiment, the present invention provides a method of sealing a tissue puncture opening in a living being that extends from an external puncture opening in a skin surface percutaneously through the tissue to a depth X, comprising the steps of inserting an elongated implant having a length greater than X into said tissue puncture opening, wherein the implant comprises a dried, swellable, resorbable matrix, and removing that portion of the implant that extends outside the external puncture opening. Such a method can be used to seal any tissue puncture opening created surgically or otherwise.
These and other features and advantages of the invention will be apparent to those skilled in the art from the following detailed description, taken together with the accompanying drawings, in which like reference numerals refer to like parts.